matrix retainer

matrix retainer,

a mechanical device used to secure the ends of a matrix band around a tooth. The band provides a substitute wall where a part of the tooth is missing and helps to compact a restoration into a prepared tooth cavity after the carious lesion has been removed. Also called matrix holder. See also retainer.

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matrix (mā´triks),

n 1. an intergranular substance that acts somewhat as a cementing material for other particles; e.g., zinc phosphate cement is made of undissolved zinc oxide particles, surrounded and held or cemented together by phosphate compounds. The phosphate compounds make up the matrix.
n 2. a mechanical or artificial wall that completes the mold into which plastic material is inserted.
n 3. a mold into which something is formed. See also bone; splint.

matrix, amalgam,

n a metal form, usually of stainless steel, about 0.0015 to 0.002 inch thick, adapted to a prepared cavity to supply the missing wall so that the plastic amalgam will be confined when it is condensed into the cavity.

matrix, celluloid,

n a strip of celluloid used to mold cement into the desired shape. See also strip, plastic.

matrix, custom,

n a matrix made especially for a given location, tooth, or preparation.

matrix, fibrous, of alveolar bone,

n collagen fibers in the alveolar bone, calcified by the accumulation of hydroxyapatite, a calcium salt.

matrix, fibrous, of bone,

n a component of bone tissue consisting of collagen fibers.

matrix, fibrous, of periodontal ligament,

n major component consisting of collagen and oxytalan fibers whose function is to provide support to the tooth.

matrix holder,

n See retainer, matrix.

matrix, intermicrobial

(in´turmīkrō´bēl),
n an intercellular substance found in plaque, which is made from derivatives of saliva, gingival fluids, and microorganisms.

matrix, mechanical,

n (proprietary matrix), a patented or manufactured type of matrix.

matrix, plastic,

n a matrix of resin or plastic for use with cold-curing resin or cement.

matrix, platinum,

n a matrix of wrought platinum foil, usually 0.001 inch or thinner, adapted to a die of a preparation for a fired porcelain restoration; serves as a vehicle to carry and maintain the applications of porcelain when they are placed in a furnace for firing.

matrix, proprietary,

n See matrix, mechanical.

matrix retainer,

n a mechanical device used to secure the ends of metal or plastic bands around a tooth to provide a form into which a restorative material can be condensed to replace a portion of tooth substance removed in cavity preparation. See also retainer, matrix.

matrix, T-band,

n a matrix material cut with a T-shaped projection at one end; the lugs are bent over to engage the band as it encircles the tooth.

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retainer,

n (retaining appliance), 1. The part of a dental prosthesis that unites the abutment tooth with the suspended portion of the bridge. It may be an inlay, partial crown, or complete crown.
n 2. an appliance for maintaining the positions of the teeth and jaws gained by orthodontic procedures.
n 3. the portion of a fixed prosthesis attaching a pontic(s) to the abutment teeth (e.g., inlay, three-quarter crown).
n 4. a form of clasp, attachment, or device used for the fixation or stabilization of a prosthetic appliance.
n 5. an orthodontic appliance, fixed or removable, used to maintain teeth in corrected positions during the period of functional adaptation following corrective treatment.

retainer, continuous bar,

n a metal bar that is attached to a major connector and contacts lingual surfaces of anterior teeth, on or incisal to the cingula; it aids in the stabilization of a distal extension removable partial denture.

retainer, direct,

n a clasp, attachment, or assembly applied to an abutment tooth for the purpose of maintaining a removable restoration in its planned position in relation to oral structures.

retainer, extracoronal,

n 1. a type of retainer in which the preparation and its cast restoration lie largely external to the body of the coronal portion of the tooth and complement the contour of the crown. The retention or resistance to displacement is developed between the inner surfaces of the casting and the external walls of the prepared tooth. The extracoronal retainer may be a partial crown or a complete crown.
n 2. a direct retainer of the clasp type that engages an abutment tooth on its external surface in such a way as to afford retention and stabilization to a removable partial denture; a direct retainer of the manufactured type, the male portion of which is attached to the external surface of a cast crown on an abutment tooth (e.g., Dalbo and Crismani attachments).

retainer, Hawley,

n.pr a wire and acrylic resin removable appliance designed to stabilize teeth after tooth movement; serves as a basis for tooth movement by providing an anchorage for the wires and rubber dam elastics used in orthodontic tooth movement.

retainer, indirect,

n that part of a removable partial denture that resists movement of a free end denture base away from its tissue support through lever action opposite the fulcrum line of the direct retention.

retainer, intracoronal,

n 1. a type of retainer in which the prepared cavity and its cast restoration lie largely within the body of the coronal portion of the tooth and within the contour of the crown (e.g., inlay). The retention or resistance to displacement is developed between the casting and the internal walls of the prepared cavity.
n 2. the type of direct retainer used in the construction of removable partial dentures; it consists of a female portion within the coronal portion of the crown of an abutment and a fitted male portion attached to the denture proper. These retainers may be fabricated in the dental office or obtained through commercial sources.

retainer, matrix,

n (matrix holder), a mechanical device designed to engage the ends of a matrix around the tooth.

retainer, radicular,

n a type of retainer that lies within the body of the tooth and is usually confined to the root portion of the tooth (e.g., dowel crown). The retention or resistance to displacement and shear is developed by extending an attached dowel into the root canal of the tooth.

retainer, resin-bonded,

n a prostheses fixed into an empty space created by a lost or congenitally missing tooth using bonding resin with intact or minimally restored abutment teeth in order to prevent abutment teeth from tilting or rotating.